"Authentication failed" when trying to add my account

Geistownjohnny wrote:

"Authentication Failed"

"Failed to authenticate with Yahoo. Try again later.

This was the result of trying to add a Yahoo email to the Apple Mail app.

https://discussions.apple.com/content/attachment/c9a576ae-43a2-4484-b6d7-5bda1ad2413d

contact yahoo support.

Geistownjohnny wrote:

Yahoo problem?

Based off the screenshot yes.

And yahoo email is notoriously bad with using 3rd party mail apps, as they push you to use their apps to access their emails.